Tread portion of an automobile tire



FIG. 1 is a front view of a tread portion of an automobile tire, the tread pattern repeating uniformly around the circumference of the tire;

FIG. 2 is a perspective view thereof;

FIG. 3 is a left side view thereof, the right side being a mirror image; and,

FIG. 4 is a fragmentary enlarged view showing the details of the tread portion thereof.

Broken lines in the drawing figures are intended to show environmental structure only, and form no part of the claimed design. 

The ornamental design for a tread portion of an automobile tire, as shown and described. 